Check-valve



(N0 Mode l.)

A. M. BRAINARD.

CHECK VALVE. No. 266,875. Patented Apr. 25, 1882} a rJE E53z3 UNITED STATES PATENT OFFICE.

ADELBERT M. BRAINARD, OF CHICAGO, lLLINOIS.

CHECK-VALVE SPECIFICATION forming part of Letters Patent No. 256,875, dated April 25, 1882. Application filed October 5, 1881. (No model.)

I and'I do hereby declare that the following is a full, clear, and exact description thereof,

reference being h ad 'to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to the valves of airpumps; and it consists in the novel features of construction and combinations hereinafter fully described, and pointed out in the claims, its object being to better prevent the escape or passage of the air through the pump checkvalve.

In the drawings, Figure l is a central vettical section of an air-forcing pump provided with my improved valve. Fig. 2 is a plan of the apcrtured plate of the valve, and Fig. 3 is a plan of the leather flap or valve proper.

The improved valve may be applied in the pump-cylinder or in the pipe or passage leading therefrom. In Fig. 1 of the drawings the valve is located at the 'foot of the cylinder of a forcing-pump.

Ais the pump-cylinder. B is the piston, and C is the handle connected with the cylinder-rod b bythe rod 0. y E is a metallic plate, having a central aperture e, and E is a flap of leather, rubber, or other suitable material, properly secured in place to cover the aperture eon the pressure side'of the plate E. Around the opening 0 the metal plate E is raised to form a sharp-edged boss or ridge, 0. These parts are shown held in place by means of the base F and cylinder A, the former being recessed and threaded to receive the latter, so that they will tightly compress the plate and flap between them. Beneath the flap E the base F is recessed to allow downward movement of the flap, and to receive a coiled or helical spring, E whose upper end bears fairly against the flap E outside or all around the aperture 6. By this means the back-pressure is excluded from between the plate E and flap E and operates to force said flap so tightly against the edged boss 6 as to form thereby a perfect check. Under piston-pressure the spring E yields to allow the air to pass the flap E.

While I prefer the helical form of the spring E shown, any other form of spring may be used, and, if thought best, an annular plate or cap may be interposed between the spring and the flap to prevent the latter from being forced down within the spring. As here shown, the piston-rod is hollow and has a hole, I), at the top to admit air through the piston, the latter being apertured and provided with any suitable form of check.

Of course in an exhaust-pump the parts forming the valve described will be reversed from the positions here shown.

I claim as my invention 1. In a check-valve, the combination of an apertured' seating-plate, E, a flexible flap, E, and a spring, E together arranged to bear around the aperture, andoperating substantially as described and for the purposes set forth.

2. In a check-valve, the combination of a seating-plate, E, having its aperture 0 surrounded with a boss, e, aflexible flap, E, and a spring, E arranged to bear all around the boss, substantiallyas and for the purposes set forth.

In testimony that I claimthe foregoing as my invention 1 aflix my signature in presence of two witnesses.

ADELBER 'I M. BRAINARD.

Witnesses:

M. E. DAYTON, W. (l. ADAMS. 

